如何在程序中切换输入法(50分)

unit Unit1;
interface
uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls;
type
  TForm1 = class(TForm)
    Memo1: TMemo;//设好imeMode属性！
    ComboBox1: TComboBox;//Text属性为空
    procedure FormCreate(Sender: TObject);
    procedure ComboBox1Change(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
var
  Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.FormCreate(Sender: TObject);
begin
  ComboBox1.Items:=Screen.Imes;//获取系统安装的所有输入法
end;
procedure TForm1.ComboBox1Change(Sender: TObject);
begin
  Memo1.ImeName:=ComboBox1.Text;//根据所选的输入法变化Memo的默认输入法
end;
end.

with Screen.Imes do
  ActivateKeyboardLayout(HKL(Objects[IndexOf('中文 (简体) - 微软拼音')]), KLF_ACTIVATE);